Study on Spectral Shapes of K.ALPHA. Lines of Ammonium and Nitrate Nitrogen Using Electron Probe Microanalyzer and Molecular Orbital Calculation

Abstract

An electron probe microanalyzer was applied to ammonium sulfate, ammonium nitrate and sodium nitrate to make chemical-state analyses of Kα lines of ammonium and nitrate nitrogen. The results inferred that the shape of the Kα lines in ammonium sulfate and ammonium nitrate was symmetric, and that of the Kα lines in sodium nitrate was asymmetric. To understand this asymmetry of the Kα lines in sodium nitrate theoretically, the electronic transition states of a nitrate ion cluster, related to the Kα lines of nitrogen, were calculated by the DV-Xα molecular orbital method. The results showed that the electronic transition states (transition energies and intensities), caused by chemical bonds between nitrogen and the adjacent oxygen atom, determined the shapes of the Kα lines of nitrogen.